U.S. Pat. Nos. 3,644,278 and 3,778,464 describe the use of N,N-dibenzylhydroxylamine and selected other substituted hydroxylamines as stabilizers for polypropylene. There is no mention of the N,N-dialkylhydroxylamines as possible stabilizers for such polyolefin compositions in these patents.
U.S. Pat. No. 4,590,231 describes the use of hydroxylamines including the N,N-dialkylhydroxylamines as stabilizers for polyolefin compositions. The N,N-dialkylhydroxylamines are described generically as having alkyl of 1 to 18 carbon atoms and N,N-dioctylhydroxylamine is specifically disclosed as useful in such compositions. There is no mention of the longer chain N,N-dialkylhydroxylamines which are the subject of this invention. The stabilized polyolefin compositions described in this patent also contain an alkaline metal salt of a fatty acid and a phenolic antioxidant. The compositions may optionally also contain a hindered amine light stabilizer or an organic phosphorus compound.
U.S. Pat. No. 3,408,422 describes the stabilization of unsaturated polyester compositions using various hydroxyl amines. N,N-Dialkylhydroxylamines of 1 to 12 carbon atoms are generically described. Only N,N-diethylhydroxylamine, N-methyl-N-amylhydroxylamine and N,N-dibutylhydroxylamine are mentioned.
U.S. Pat. No. 3,644,244 describes the use of hydroxylamines including the N,N-dialkylhydroxylamines as stabilizers to prevent the gelation of organosols of butadiene/acrylonitrile graft copolymers. N,N-Dialkylhydroxylamines of 2 to 12 carbon atoms are generically disclosed, but only N,N-diethylhydroxylamine is specifically mentioned.
U.S. Pat. No. 4,242,224 describes the use of dialkylhydroxylamines to reduce or retard the pink discoloration found in amine antioxidant and antiozonant emulsions used in the rubber industry. N,N-Dialkylhydroxylamines of 2 to 12 carbon atoms are again generically disclosed, but only N,N-diethylhydroxylamine is specifically mentioned.
U.S. Pat. No. 4,316,996 pertains to the use of hydroxylamine compounds which can prevent the discoloration of phenolic antioxidants in rubber compositions. N,N-Dialkylhydroxylamines of 1 to 18 carbon atoms are generically described, but once again only N,N-diethylhydroxylamine is specifically mentioned.
U.S. Pat. No. 4,547,532 pertains to the use of hydroxylamines to prevent the premature increase in viscosity of polymer-based antifouling paints containing an organotin compound. N,N-Dialkylhydroxylamines of 1 to 20 carbon atoms are generically described, but only N,N-dimethylhydroxylamine, N,N-diethylhydroxylamine and N,N-dibutylhydroxylamine are specifically disclosed.
U.S. Pat. No 4,409,408 discloses the use of N,N-dialkylhydroxylamines and tertiary alkylcatechols in stabilizing vinyl aromatic compounds, such as styrene, against premature polymerization. N,N-Dialkylhydroxylamines of 2 to 10 carbon atoms are generically disclosed. N,N-Didecylhydroxylamine is specifically mentioned, but not exemplified and the preferred N,N-dialkylhydroxylamines are of 2 to 6 carbon atoms.
L. A. Harris et al., J. Am. Oil Chemists Soc., 43, 11 (1966) specifically discloses N,N-dioctylhydroxylamine, N,N-didecylhydroxylamine and N,N-didodecylhydroxylamine. These hydroxylamines are shown to have antioxidant activity in squalene.
U.S. Pat. No. 3,770,847 discloses N,N-didodecylhydroxylamine. The hydroxylamines of this patent are disclosed as curing catalysts for organopolysiloxane compositions. The lower alkyl hydroxylamines are superior for this purpose.
U.S. Pat. No. 4,298,678 pertains to photosensitive compositions which contain substituted hydroxylamines. N,N-Diethylhydroxylamine is the preferred embodiment, but N,N-ditetradecylhydroxylamine is disclosed and N,N-didodecylhydroxylamine is exemplified in such compositions.
None of these references describes the very long chain N,N-dialkylhydroxylamines of over 14 carbon atoms nor does any of said references suggest that the long chain N,N-dialkylhydroxylamines of the instant invention exhibit special properties not possessed by the lower alkyl N,N-dialkylhydroxylamines which are usually the preferred embodiments in the cited prior art.